Abstract:
Curcumin is an active pharmaceutical ingredient (API) present in the Indian spice turmeric, Curcuma longa. Among theseveral solid-state properties of an API, dissolution has an immediate effect on its bioavailability. Inspite of its medicinalproperties, curcumin has very low aqueous solubility. Efforts have been already made for increasing solubility andbioavailability of curcumin by preparing various solid forms. In this work attempts have been made to investigatecocrystallization of curcumin with various coformers. The work focused on understanding curcumin cocrystallization withcoformers namely N-acetyl D, L-Tryptophan, tyrosine, glycine, biotin, paracetamol, carbamazepine, ibuprofen, folic acid,suberic acid, succinic acid, ethyl paraben and dextrose. The coformers chosen belong to different categories like amino acids,API, acids and sugars. Binary Phase diagrams were constructed for the investigated systems. The relationship betweenmelting point and dissolution properties has been analyzed in detail. With the obtained phase diagrams, attempts have beenmade to correlate the dissolution properties of each system with curcumin. Cocrystallization of curcumin with ethyl paraben(Eutectic melting temperature: 110.3 °C) and succinic acid (Eutectic melting temperature: 154.2°C) resulted in formation ofeutectic mixtures whereas with ibuprofen and dextrose, curcumin resulted in a physical mixture. In depth understanding ofthe explored systems are being developed by characterizing the physical mixtures, eutectic mixtures or cocrystals by FTIRanalysis, solid-state NMR and single crystal X-RD analysis. This will be followed by investigating the extent of dissolutionachieved by the solid forms. This kind of thorough investigation will enable us to fine-tune the solubility of curcumin bychoosing structurally-related coformers that can potentially enhance solubility of curcumin.